Thank you. Very nice explanation and helpful insights.
The Subversion revision number in the manifest can help us to answer many useful questions (where is the source code for file A, what changes were made to file A for this deploy, when was the last time file A was changed) by examining the repository history.
Suppose one file in the production directory is accidently deleted and is restored from a backup site. We cannot be sure this file belongs to Subversion revision 10 (that there was no mistake in selecting the backup) by examining the file.
Suppose someone accidently overwrites a file (copies a file to production instead of test, or copies TO the directory instead of FROM the directory, etc.) or maybe intentionally replaces one file. Other than the filesize and timestamp, the file does not tell us where it came from.
Is that correct?